package com.us.util;

public class ByteUtil {

    /**
     * 字符数组转化为 16进制的字符串
     * 
     * @param array
     * @return 把字节数组变为16进制字符串
     */
    public static String byte2hex(byte[] input) throws Exception {
        StringBuilder sb = new StringBuilder();
        String stmp = "";
        for (byte b : input) {
            stmp = Integer.toHexString(b & 0XFF);
            if (stmp.length() == 1) {
                sb.append("0" + stmp);
            } else {
                sb.append(stmp);
            }
        }
        return sb.toString();
    }

    /**
     * 十六进制的字符串转化为字节数组
     * 
     * @author monlyu
     * @since 2010-1-22
     */
    public static byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0)
            throw new IllegalArgumentException("长度不是偶数");
        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);
            b2[n / 2] = (byte) Integer.parseInt(item, 16);
        }
        return b2;
    }

    /**
     * 把字符串转化为字节数组,不足八位的补足0
     * 
     * @author monlyu
     * @param str
     *        入字符串
     * @param bei
     *        必须多少为
     * @since 2010-1-23
     */
    public static byte[] strTo8byte(String str) {
        byte[] oriByte = str.getBytes();// 23
        int left = oriByte.length % 8;// 7
        int pei = oriByte.length / 8;// 2
        if (left == 0) {
            return oriByte;
        }
        byte[] value = new byte[(pei + 1) * 8];
        for (int i = 0; i < value.length; i++) {
            value[i] = (byte) (i < oriByte.length ? oriByte[i] : '0');
        }
        return value;
    }
}
